Combines having concaves for threshing of grain are common in the farming industry. Conventional concaves include a plurality of spaced-apart bars which are mounted such that in cross section they are aligned with respect to a radial line passing from the center of the combine cylinder through each of the bars. Such a construction of the concave often results in a problem that the grain separated from the stalks often is carried beyond the concave to be discharged with the stalks rather than falling through the concave to be separated from the stalks. The conventional concave is thus inefficient in that it fails to collect all of the grain separated from the stalks.
Therefore, a primary objective of the present invention is an improved combine concave for facilitating the movement of grain between the concave bars.
A further objective of the present invention is the provision of an improved combine concave in which the resistence of the concave bars to the passage of grain therebetween is minimized.
A further objective of the present invention is the provision of a combine concave which is economical to manufacture and durable in use.